1. Field of The Invention
This invention relates to object image indicating apparatus, and more particularly to an object image indicating appratus in which an object image memory stores object images as coordinate picture element information in the vertical or horizontal direction and the coordiante picture element information is read out of the object image memory to be raster image-indicated on a CRT.
2. Prior Art
There has been known an object image indicating apparatus which indicates a specified picture image as an object on a CRT image display screen with a determined scale up or scale down factor, and is widely used for various types of simulators, design drawing systems, video games and other instruments.
For example, a flight simulator to be used for training the crews of the airplane models a real airplane cockpit and is equipped with a CRT in front of operating seats together with meters and gauges to display picture scenes of surface during flight. In case of shamming a taking-off or a landing of airplane it is required to display the pictures of runway and its vicinity with a scale up or scale down factor in order to simulate a real flight. The object image indicating apparatus is thus used in the above mentioned application.
For another example, in design drawing systems there are many cases in which a part of or all of the certain drawing displayed on a CRT is required to get scaled up or down. The object image indicating apparatus is thus used in the above mentioned application.
Furthermore, in recently popularized video games, a target displayed on a CRT is indicated with scale up or scale down in accordance with a game in progression in order to make this game more enjoyable. The object image indicating apparatus is thus used in the above mentioned application.
FIG. 1 is a schematic block diagram showing a simple composition of the above mentioned image indicator, wherein, as shown in FIG. 2, object images are stored in a object image memory 10 as coordinate picture element information in the vertical or horizontal direction, and character codes for reading the objects out are provided for the respective objects thus stored. Then, the object images specified by the character codes are read out of the object image memory 10 by an image processing circuit 12 and raster image-indicated on a CRT 14.
Here, since read-out actions of object images from the object image memory 10 are effected on each line in responce to a horizontal synchronizing signal of raster scanning, an object is raster image-displayed on the CRT, the sizes of the object displayed on the CRT are determined by the sizes stored in the object image memory 10. In other words, the sizes displayed on the CRT are determined by the numbers of memory bit being used for the object images to be sorted in the object image memory 10.
Accordingly, in order to display an object on the CRT with scale up or scale down by using the object image indicating apparatus a plurality of object images must be stored in the object image memory 10 with different sizes per one object, thereby presenting such a disadvantage that numbers of the object images must be stored in the object image memory 10 per one object in order to have an object be displayed on the CRT with more precise scale up or scale down factor.
Therefore, since in the object image indicating apparatus in the prior art a plurality of object images must be stored with different sizes for one kind of object, the object image memory 10 must use a memory device with extremely large storage, thereby also presenting such disadvantage that the small memory storage could limit the kinds of objects to be stored in the object image memory 10.